The present invention disclosed herein relates to a substrate treating apparatus. More specifically it relates to a chemical supply unit for supplying a chemical fluid for substrate treatment and apparatus for substrate treating.
Conventionally, in a method for manufacturing a semiconductor substrate, processes such as a film deposition process, an etching process and a cleaning process are performed. Particularly, a wet etching process and a cleaning process treat the semiconductor substrate by using various chemical fluids.
A chemical fluid treating apparatus for supplying a chemical fluid to a substrate treating apparatus such as a wet etching device or a cleaning device controls concentration and temperature of the chemical fluid and supplies the chemical fluid. The chemical fluid treating apparatus obtains a storage tank and controls the concentration of the chemical fluid within the storage tank and supplies to the substrate treating apparatus.
This kind of substrate treating apparatus comprises a spin head seated on the semiconductor substrate and a nozzle for exhausting a chemical fluid to the substrate seated on the spin head. The nozzle is connected to a supply line and the supply line receives a chemical fluid from the chemical fluid treating apparatus and provides it to the nozzle. The supply line comprises a control valve for controlling the amount of chemical fluid supplied to the nozzle and a suck-back valve for removing remaining chemical fluids in the nozzle by suck-backing chemical fluids. When the valve is off and blocks the chemical fluid supplied to the nozzle, the suck-back valve suck-backs the chemical fluids remaining in the nozzle and prevents remaining chemical fluids leaking to the outside.
Recently, chemical liquid drop phenomenon has been increased since the nozzle discharge hole got bigger to increase the amount of chemical liquid discharge. In case of chemical liquid, a surface-active component, and a chemical liquid having low viscosity (IPA, or ozone including solution), a surface tension is very low thereby even with suck-backing, the chemical liquid within the supply line may flow to the nozzle and discharged to the outside. Particularly, when there is an impact from outside, a chemical fluid remaining close to the discharge hole on a path of the nozzle may intermittently drop.
Therefore, excessive chemical fluid contaminates and damages a substrate and when this repeats a desired substrate may not be produced. Moreover, in using a plurality of nozzle discharge holes to clean a substrate, when unwanted chemical liquid runs out, it causes a substrate or a spin head to be contaminated and cleaning efficiency drops. Therefore, it causes a decrease in productivity.